Multimedia presentations are a popular method of disseminating information to large numbers of people. The presentations may take place in a number of settings, such as meetings, conferences, educational settings and so on. The presentation may also take various forms, including video or audiovisual presentations. Sometimes, the image projection equipment may be placed in various locations and/or at various angles with respect to a projection screen for a number of reasons, including to increase the ability of the audience to view the images on the projection screen or because there may be no available surface to place the image projection system at a right angle to the projection screen.
An issue that is common to many image projection systems is image distortion. An image projection system that is placed at a non-right angle with respect to the projection screen may result in distortion of the projected image on the projection screen. For example, the image for projection may be a square, but the projected image on the projection screen may appear to the viewers as a trapezoid, may appear elongated and so on. Correcting image distortion is referred to as “keystone correction” or “keystoning.”
A common keystoning method is to manipulate the position of the image projection system with respect to the projection screen so that the projected image becomes less distorted. Many current keystoning methods require multiple adjustments by the presenter to address the distorted image or the image processing system may have difficulty with image recognition in environments with various lighting conditions. Thus, a method of keystoning and a keystoning system that may operate with minimal interaction by the presenter as well as an image processing system that may function in environments having differing lighting conditions may be useful. Accordingly, there is a need in the art for an improved method of keystoning.